It is generally known that the Prins cyclization1 of an aldehyde and a homoallylic alcohol provides a powerful access to tetrahydropyran-4-ols. Enantiomers/diastereomers of 2,4-disubstituted-tetrahydropyran-4-ol (a type of tetrahydropyran-4-ol) and its derivatives display different intensity of odor. Further, according to the prior art, the synthesis of enantiomers of 2,4-disubstituted-tetrahydropyran-4-ol and its derivatives require 5-7 synthetic steps.2 
Numerous protonic acids and Lewis acids are known to catalyze Prins cyclization and excellent reviews have been published on the earlier work.3, 4     (1) Snider, B. B. In Comprehensive Organic Synthesis; Trost, B., Fleming, I., Heathcook, C. H., Eds.; Pergamon: New York, N.Y., 1991; Vol. 2, pp 527-561.    (2) Abate, A.; Brenna, E.; Fronza, G.; Fuganti, C.; Gatti, F. G.; Serra, S.; Zardoni, E. Helv. Chim. Acta 2004, 87, 765-780.    (3) Pastor, I. M.; Yus, M. Curr. Org. Chem. 2007, 11, 925-957.    (4) Olier, C.; Kaafarani, M.; Gastaldi, S.; Bertrand, M. P. Tetrahedron 2010, 66, 413-445.
However, the reactions as described in the prior publication at 2 above discloses a multi-step process for synthesis of chiral 2,4-disubstituted-tetrahydropyran-4-ol and its acetate derivative and hence results in a low yield of the final product. Also, the use of a chiral organocatalyst is not taught anywhere. On the contrary, they teach use of a biocatalyst during the reaction process which is more expensive and hence makes the process commercially unviable.
Further, recent patents WO2010/133473 A1, US 2011/0306779 A1 disclose a process for the preparation of 2-substituted-4-hydroxy-4-methyl-tetrahydropyran by treating isoprenol with an aldehyde and wherein the said reaction is carried out in the presence of water and strongly acidic cation exchanger, which are not chiral. Whereas patents US2014/0107352 A1 and WO 2014/060345 A1 relate to integrated preparation of 2-substituted 4-hydroxy-4-methyltetrahydropyrans and of 2-substituted-4-methyltetrahydropyran in the presence of acid catalysts such as hydrochloric or sulfuric acid but preferably methanesulfonic or p-toluenesulfonic acid or strongly acidic cation exchanger, followed by fractionation of reaction products and reduction of olefinic fraction by hydrogenation reaction.
However, the said prior art does not disclose the use of 1-(R) or 1-(S) camphor sulfonic acid as a chiral organocatalyst. Hence the present invention provides the synthesis of chirally enriched 2, 4-disubstituted-tetrahydropyran-4-ol, through the use of chiral organocatalyst, which is inexpensive, making the entire process commercially viable. Moreover, the organocatalyst described in the present invention yields enantiomerically enriched products in environmentally benign conditions, which is why it is also termed as green process.